Electric switch plug and socket indicator



July 31 1945.

| FRANK ELECTRIC SWITCH FLUG AND SOCKET INDICATOR 1 Filed Aug. l4, 1945 7 2 shee ts s heet 1 v. x 74 3.4; mi-m! Ill/III,

I i Y bvmvroze. Lou/:5 RAN mime/v v Patented July 31, 1945 OFFICE ELECTRIC SWITCH PLUG AND SOCKET INDICATOR Louis Frank, Fellows, Calif.

Application August 14, 1943, Serial No. 498,664

3 Claims.

My invention relates to electric switch plugs and sockets of the chain pull type and the principal object of my invention is, to provide such plugs with simple and efficient means for indicating whether or not the movable contacts within the switch and which control the passage of electric current therethrough, are in open or closed positions, thus eliminating all uncertainty as to the on or off condition of the switch and minimizing the possibility of electric shocks and consequent burns, also wasteful use of electric current.

A further object of my invention is. to Provide a simple and practical form of indicating means which may be readily combined with practically all forms of switch plugs having pull actuated, rotary make and break contacts.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts which will be hereinafter more fully described and claimed and illustrated in the accompanyin drawings in which:

Fig. 1 is a front elevation of a switch plug equipped with my improved indicating means.

Fig. 2 is an enlarged horizontal section taken on the line 2-2 of Fig. 1.

Fig. 3 is a horizontal section similar to Fig. 2 with the operating parts of the indicator shown in plain view.

Fig. 4 is a fragmentary view taken on the line 4-4 of Fig. 3.

Fig. 5 is a perspective view of the rotating drum which carries the indicating means on its front face.

Fig. 6 is a fragmentary perspective view of the front end of the rotary drum.

Fig. 7 is a horizontal section taken through the center of the drum and showing the detent therefor.

Fig. 8 is a perspective view s'h'owing disassembled, the pull chain operated disc and the link which connects the chain thereto.

Fig. 9 is a front elevation of a modified form of the switch plug.

Fig. 10 is an enlarged elevational view of the upper portion of the plug with the housing removed.

Fig. 11 is a section taken on the line ll--ll of Fig. 10.

Fig, 12 is a vertical section taken on the line i-l2 of Fig. 10.

Fig. 13 and 14 are perspective views of operating parts of the form 01' indicator illustrated in Figs. 9, 10. 11 and 12.

Fig. 15 is a horizontal section taken on the line |li5 of Fig. 12.

Fig. 16 is a view looking against the underside 01 a vibrating arm used in the indicator.

Referring by numerals to the accompanying ill ZOO-51.15)

drawings and particularly to the form of indicator illustrated in Figs. 1 to 8 inclusive, i0 and i I designate respectively the front and rear parts of a conventional switch plug and socket body, same being divided on a medial vertical plane and secured to each other by a screw I2.

A chamber 13 is formed between the body members Hi and H and seated in the rear member H and projecting forwardly into this chamber is a pin It on which is mounted for rotation, a disc I! of insulation.

This disc l5 carries on its rear face, parts which actuate the movable members of the conventional make and break contacts which control the current flow through the switch.

Secured on the front face of disc 15 is one end of a curved flat spring l8, approximately 180 in length and the free end of which is spaced apart from the face of said disc.

0n the fixed end of this spring is a hook ll to which is connected by a link It one end of a pull chain 19 that passes downward behind disc 15 and out of the plug body through a side opening 20. The parts just described are arranged so that when chain I9 is pulled, disc 15 and spring 16 carried thereby are rotated degrees.

Mounted to rotate on the forward portion of pin H is a disc 21 which is formed integral with a drum 22, the rear end of the latter which terminates adjacent disc I! being provided with four shoulders 23 disposed 90 degrees apart. The free end of spring 16 is adapted to engage these shoulders, thus serving as a pawl in imparting rotary motion to the drum and its disc.

On the front face of disc 2| are four recesses 24 disposed 90 degrees apart and between said recesses are markings such as "on" and "off" or spots of color such as red and black or black and white and which markings are visible through a window 25 in the front wall of body It, thus in dicating the condition of the switch 1. e. whether it is open or closed.

The rear face of disc 2| bears against a smaller disc 26 carried by pin H and formed on the rear face of said disc 28 around the pin, is a block 21 on which is mounted a cup 28, from which projects a short finger 29. Connected to this finger is the forward end of an expansive coil spring 30, the rear end of which is connected to disc l5 so that the latter is held at its rearward limit of movement against the movable contacts of the switch and cup 28 is held in position on block 21. Spring 30 has sufilcient torsion to yieldingly resist pull of the chain l9 and disc l5 and to cause the latter to return to it normal position after being partially rotated and pull on the chain is relieved.

Mounted on the forward end of pin I4, is a convex resilient arm 3|, the free end of which functions as a detent to enter the recesses 24 in the face of disc 2! thus yieldingly holding the latter 7 in predetermined positions at the ends of the parthe switch.

As disc I5 is thus rotated the end of sprin I6 engages one of shoulders on the rear end of drum 22 and rotates 90 degrees and at the end of arm 3| enters one of the recesses 24 to hold the disc 2| and drum 22 against reverse movement,

as disc l5 and spring l6 return to their normal positions under the torsional action of spring 30.

The markings on the face of disc 2! are disposed in proper relation to the open and closed positions of the switch contacts actuated by disc l5 and thus, as the drum 22 and disc 2| are in-' termittently rotated, as just described, the proper marking or indication will appear through the window 25 to show the condition of the switch, that is, whether the same is open or closed.

The form of indicator illustrated in Figs. 9 to 16 inclusive is designed for use in switch plugs wherein the pin or shaft on which the contact actuating means is vertically disposed and in this construction designates the main body of the plug 36, the upper member of the body. with an opening 31 between said body, 38 the usual shell of casing and 36 the cap.

Mounted for rotation in the body 35 is a vertically disposed pin or shaft 46, the upper portion of which projects upwardly in a chamber 4!, in upper member 36 and on the upp r end of said pin is head 42, which bears against a shoulder in the upper portion of chamber,4i. Head 42 is square or non-circular and normally occupies a square or non-circular recess 44 in the upper portion of chamber 41 so as to maintain pin against rotation.

Head 42 is provided with a slot 4i. for the reception of a screw driver which may be entered through the upper portion of chamber 4| and used to move the pin downwardly to withdraw head 42 from recess 44, and thereby permit the pin to be rotated.

Mounted for rotation on pin 45 in the bottom of chamber 31 is a disc 45 of insulation having an arm 46 to which is connected one end of a pull chain 41 that projects outward through chamber 31.

Secured to the disc 45 is the lower end of an expansive torsional coil spring 48, the upper end thereof being secured to head 42.

Secured to the upper face of disc 45 is one end of a spring arm 43, the free end of which terminates'ina hook 50 which occupies a horizontal plane above said disc.

The under face of disc 45 carries the conventional ratchet plate R for actuating contacts 01 the switch. Journalled on a vertical axis 5| in upper member 36 above the chamber 31 is a vertically disposed drum 52 provided on its lower end with a series of ratchet teeth 53 with which hook 50 is adapted to engage as disc 45 and arm 46 are vibrated by pull chain 41.

Disc 45 rotates 90 degrees with each pull of chain 41 and due to the small diameter of drum 62, it may only, to function properly, rotate 60 degrees with each actuation by spring 49. Thus there are six teeth 53 on drum 52 and said teeth being disposed 60 degrees apart. Thus hook 50 moves 15 degrees before it engages one of the teeth 53 and after moving same 60 degrees the hook rides onto a shoulder or rise 54 on the upper face of chamber 31 to the side or drum 52, so that said hook will be moved downward, out of contact with the engaged tooth and then travel 15 degrees further to complete its stroke of 90 degrees.

To hold the drum after it has been rotated 60 degrees the free end oi a spring detent 55 engages in one of a series of six recesses 56 which are formed in the face of the hub of drum 52 and which detent is secured to body 36 to the side of said drum (see Fig. 11).

The race of drum 52 between the recesses 56 bears indication characters, words or color to indicate the on and "off positions of the movable contacts in the switch and which latter contact the flow of current through said switch. These characters are visible through a window 51 in the upper body member 36. Thus as the chain 41 is pulled to actuate the movable contacts of the switch, the drum will be partially rotated by hook 50 on arm 49 and the proper indicating word, color or character will be brought into view through window 51.

The torsion of spring 48 returns disc 45 to its normal position after having been actuated as a result of pull on the chain.

Thus it will be seen that I have provided a switch plug and socket indicator which is simple in structure, inexpensive of manufacture and very effective in performing the functions for which it is intended.

It will be understood that minor changes in the size, form and construction of the various parts of my improved switch plug and socket indicator may be made and substituted for those herein shown and described, without departin from the spirit of the invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. The combination with a switch plug and socket having a chamber containing theusual fixed and movable contacts, of a horizontally disposed pin seated in the upper portion of said chamber, a disc of insulation mounted for rotation upon said pin for actuating said movable contacts, an arcuate' spring mounted on the rear face of said disc, one end of which spring is spaced apart from the disc to form a resilient pawl, a link secured to the other end of said spring, a pull chain attached to said link and extending outwardly from the chamber in the body of said plug and socket, a member mounted for rotary movement on said pin and bearing on its front face, indicia to indicate the positions of the switch contacts and the rear end of which rotarymember is provided with ratchet teeth which are engaged by said resilient pawl.

2. The combination as set forth in claim 1 in cluding an expansive spring between said disc and said indicia bearing member.

: 3. The combination as set forth in claim 1 with said rotary member provided on its front face with spaced recesses corresponding with the teeth on the rear end of said rotary member and a resilient detent mounted on said pin, the free end of which detent is adapted to yieldingly engage in said recess.

' LOUIS FRANK. 

